open source alternative to Rumpus
 

Hi

I'm looking for a web file transfer open-source alternative to Rumpus.

That's basically just an ftp server as far as I can tell.
For a more advanced option there are many different PHP based content management packages that you could use to implement a web access version.

Might I suggest that, instead of asking for the alternative to such a specific package, you explain what you would like to do and we can suggest suitable approaches?

There are many ftp servers, http servers and ssh servers available in the repositories of most distros. Any one of them would be suitable.